401656531 has 4 divisors (see below), whose sum is σ = 402363000. Its totient is φ = 400950064.

The previous prime is 401656529. The next prime is 401656537. The reversal of 401656531 is 135656104.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 401656531 - 2¹ = 401656529 is a prime.

It is a super-2 number, since 2×401656531² = 322655937789907922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 401656493 and 401656502.

It is not an unprimeable number, because it can be changed into a prime (401656537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 352381 + ... + 353518.

It is an arithmetic number, because the mean of its divisors is an integer number (100590750).

Almost surely, 2^401656531 is an apocalyptic number.

401656531 is a deficient number, since it is larger than the sum of its proper divisors (706469).

401656531 is an equidigital number, since it uses as much as digits as its factorization.

401656531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706468.

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 401656531 is about 20041.3704870700. The cubic root of 401656531 is about 737.8220176061.

The spelling of 401656531 in words is "four hundred one million, six hundred fifty-six thousand, five hundred thirty-one".